DotLambda: add parser recovery

dotnet · Nov 7, 2023 · ae4676d · ae4676d
1 parent 24ef671
commit ae4676d
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Showing 7 changed files with 99 additions and 13 deletions.
diff --git a/src/Compiler/SyntaxTree/SyntaxTrivia.fs b/src/Compiler/SyntaxTree/SyntaxTrivia.fs
@@ -79,7 +79,7 @@ type SynExprLambdaTrivia =
 type SynExprDotLambdaTrivia =
     {
         UnderscoreRange: range
-        DotRange: range
+        DotRange: range option
     }
 
 [<NoEquality; NoComparison>]

diff --git a/src/Compiler/SyntaxTree/SyntaxTrivia.fsi b/src/Compiler/SyntaxTree/SyntaxTrivia.fsi
@@ -123,7 +123,7 @@ type SynExprLambdaTrivia =
 [<NoEquality; NoComparison>]
 type SynExprDotLambdaTrivia =
     { UnderscoreRange: range
-      DotRange: range }
+      DotRange: range option }
 
 /// Represents additional information for SynExpr.LetOrUse
 [<NoEquality; NoComparison>]

diff --git a/src/Compiler/pars.fsy b/src/Compiler/pars.fsy
@@ -4882,7 +4882,7 @@ atomicExpr:
         let mDot  = rhs parseState 2
         parseState.LexBuffer.CheckLanguageFeatureAndRecover LanguageFeature.AccessorFunctionShorthand (unionRanges mUnderscore  mDot )
         let expr, hpa = $3
-        let trivia: SynExprDotLambdaTrivia = { UnderscoreRange = mUnderscore ; DotRange = mDot  }
+        let trivia: SynExprDotLambdaTrivia = { UnderscoreRange = mUnderscore ; DotRange = Some mDot  }
         SynExpr.DotLambda(expr, unionRanges mUnderscore  expr.Range, trivia), false }
 
   | UNDERSCORE DOT appExpr recover %prec dot_lambda
@@ -4891,9 +4891,28 @@ atomicExpr:
         parseState.LexBuffer.CheckLanguageFeatureAndRecover LanguageFeature.AccessorFunctionShorthand (unionRanges mUnderscore  mDot )
         reportParseErrorAt (rhs parseState 1) (FSComp.SR.parsUnderScoreDotLambdaNonAtomic())
         let expr = $3
-        let trivia: SynExprDotLambdaTrivia = { UnderscoreRange = mUnderscore ; DotRange = mDot  }
-        SynExpr.DotLambda(expr, unionRanges mUnderscore  expr.Range, trivia), false }    
-
+        let trivia: SynExprDotLambdaTrivia = { UnderscoreRange = mUnderscore ; DotRange = Some mDot  }
+        SynExpr.DotLambda(expr, unionRanges mUnderscore  expr.Range, trivia), false }
+
+  | UNDERSCORE DOT recover %prec dot_lambda
+      { let mUnderscore = rhs parseState 1
+        let mDot = rhs parseState 2
+        parseState.LexBuffer.CheckLanguageFeatureAndRecover LanguageFeature.AccessorFunctionShorthand (unionRanges mUnderscore mDot)
+        let expr = arbExpr ("dotLambda1", mDot.EndRange)
+        let trivia: SynExprDotLambdaTrivia = { UnderscoreRange = mUnderscore ; DotRange = Some mDot  }
+        SynExpr.DotLambda(expr, unionRanges mUnderscore expr.Range, trivia), false }
+
+  | UNDERSCORE recover %prec dot_lambda
+      { let mUnderscore = rhs parseState 1
+        parseState.LexBuffer.CheckLanguageFeatureAndRecover LanguageFeature.AccessorFunctionShorthand mUnderscore
+        let mExpr = mUnderscore.EndRange
+
+        if not $2 then reportParseErrorAt mExpr (FSComp.SR.parsUnexpectedEndOfFileExpression())
+
+        let expr = arbExpr ("dotLambda2", mExpr)
+        let trivia: SynExprDotLambdaTrivia = { UnderscoreRange = mUnderscore ; DotRange = None }
+        SynExpr.DotLambda(expr, mUnderscore, trivia), false }
+
   | atomicExpr HIGH_PRECEDENCE_BRACK_APP atomicExpr
       { let arg1, _ = $1
         let arg2, hpa = $3

diff --git a/tests/FSharp.Test.Utilities/Compiler.fs b/tests/FSharp.Test.Utilities/Compiler.fs
@@ -2,6 +2,7 @@
 
 namespace FSharp.Test
 
+open FSharp.Compiler.CodeAnalysis
 open FSharp.Compiler.Interactive.Shell
 open FSharp.Compiler.IO
 open FSharp.Compiler.Diagnostics
@@ -148,6 +149,13 @@ module rec Compiler =
         | FSharpDiagnosticSeverity.Warning -> Warning errorNumber
         | FSharpDiagnosticSeverity.Error -> Error errorNumber
 
+    let getParsingErrors (parseResults: FSharpParseFileResults) =
+        parseResults.Diagnostics |> Array.map (fun x ->
+            let range = x.Range
+            let error = mapDiagnosticSeverity x.Severity x.ErrorNumber
+            error, Line range.StartLine, Col range.StartColumn, Line range.EndLine, Col range.EndColumn, x.Message
+        )
+
     type Line = Line of int
     type Col = Col of int
 

diff --git a/tests/service/Common.fs b/tests/service/Common.fs
@@ -12,6 +12,7 @@ open FSharp.Compiler.Diagnostics
 open FSharp.Compiler.Symbols
 open FSharp.Compiler.Syntax
 open FSharp.Compiler.Text
+open FSharp.Test.Compiler
 open TestFramework
 open FsUnit
 open NUnit.Framework
@@ -364,6 +365,8 @@ let getParseAndCheckResults50 (source: string) =
 let getParseAndCheckResults70 (source: string) =
     parseAndCheckScript70("Test.fsx", source)
 
+let checkParsingErrors expected (parseResults: FSharpParseFileResults) =
+    getParsingErrors parseResults |> shouldEqual expected
 
 let inline dumpDiagnostics (results: FSharpCheckFileResults) =
     results.Diagnostics

diff --git a/tests/service/ParserTests.fs b/tests/service/ParserTests.fs
@@ -3,6 +3,7 @@
 open FSharp.Compiler.Service.Tests.Common
 open FSharp.Compiler.Syntax
 open FSharp.Compiler.Text
+open FSharp.Test.Compiler
 open FsUnit
 open NUnit.Framework
 
@@ -368,3 +369,65 @@ match () with
     match exprs with
     | SynExpr.Match(_, _, [_; _], _, _) -> ()
     | _ -> failwith "Unexpected tree"
+
+
+[<Test>]
+let ``Dot lambda - Recovery _.`` () =
+    let parseResults, _ = getParseAndCheckResults """
+(_.)
+    """
+    let expr = getSingleExprInModule parseResults.ParseTree
+    match expr with
+    | SynExpr.Paren(expr =
+        SynExpr.DotLambda(
+            expr = SynExpr.ArbitraryAfterError("dotLambda1", exprRange)
+            range = lambdaRange
+            trivia = { UnderscoreRange = underscoreRange; DotRange = Some dotRange }
+     )) ->
+        assertRange (2, 3) (2, 3) exprRange
+        assertRange (2, 1) (2, 3) lambdaRange
+        assertRange (2, 2) (2, 3) dotRange
+    | tree -> failwith $"Unexpected tree: {tree}"
+
+    parseResults
+    |> checkParsingErrors [|Error 10, Line 2, Col 3, Line 2, Col 4, "Unexpected symbol ')' in expression"|]
+
+[<Test>]
+let ``Dot lambda - Recovery _`` () =
+    let parseResults, _ = getParseAndCheckResults """
+(_)
+    """
+    let expr = getSingleExprInModule parseResults.ParseTree
+    match expr with
+    | SynExpr.Paren(expr =
+            SynExpr.DotLambda(
+            expr = SynExpr.ArbitraryAfterError("dotLambda2", exprRange)
+            range = lambdaRange
+            trivia = { UnderscoreRange = underscoreRange; DotRange = None }
+     )) ->
+        assertRange (2, 2) (2, 2) exprRange
+        assertRange (2, 1) (2, 2) lambdaRange
+    | tree -> failwith $"Unexpected tree: {tree}"
+
+    parseResults
+    |> checkParsingErrors [|Error 10, Line 2, Col 2, Line 2, Col 3, "Unexpected symbol ')' in expression. Expected '.' or other token."|]
+
+[<Test>]
+let ``Dot lambda - Recovery _ - eof`` () =
+    let parseResults, _ = getParseAndCheckResults """
+1 |> _"""
+    let exprs = getSingleExprInModule parseResults.ParseTree
+    match exprs with
+    | SynExpr.App(argExpr =
+        SynExpr.DotLambda(
+            expr = SynExpr.ArbitraryAfterError("dotLambda2", exprRange)
+            range = lambdaRange
+            trivia = { UnderscoreRange = underscoreRange; DotRange = None }
+     )) ->
+        assertRange (2, 6) (2, 6) exprRange
+        assertRange (2, 5) (2, 6) lambdaRange
+    | tree -> failwith $"Unexpected tree: {tree}"
+
+    parseResults
+    |> checkParsingErrors [|Error 3116, Line 2, Col 6, Line 2, Col 6, "Unexpected end of input in expression"|]
+
diff --git a/tests/service/XmlDocTests.fs b/tests/service/XmlDocTests.fs
@@ -193,13 +193,6 @@ let checkSignatureAndImplementation code checkResultsAction parseResultsAction =
     checkCode getParseAndCheckResults
     checkCode getParseAndCheckResultsOfSignatureFile
 
-let checkParsingErrors expected (parseResults: FSharpParseFileResults) =
-    parseResults.Diagnostics |> Array.map (fun x ->
-        let range = x.Range
-        let error = mapDiagnosticSeverity x.Severity x.ErrorNumber
-        error, Line range.StartLine, Col range.StartColumn, Line range.EndLine, Col range.EndColumn, x.Message)
-    |> shouldEqual expected
-
 [<Test>]
 let ``xml-doc eof``(): unit =
     checkSignatureAndImplementation """